Displaying 20 results from an estimated 20000 matches similar to: "fraction [a] a partitioning of variation"
2013 Aug 22
1
varpart
Dear R-users
I applied vegan's varpart function to partition the effects of
explanatory matrices. Adj. R square for the unique fraction [a] is
0.25. Does anyone know why the decomposition by hand using rda gives
me a different result for [a] (constrained proportion is 0.32)? I used
cbind() for the conditional fractions, but it should be similar to
condition()?
Thanks very much
2007 Apr 27
1
partitioning variation using the Vegan CCA routine?
Hello
I am using Jari Oksanen's CCA routine from the Vegan package on some estuary
data, following a technique applied in (Anderson, M.J. & Gribble, N.A.,
1998, Partitioning the variation among spatial, temporal and environmental
components in a multivariate data set, Australian Journal of Ecology 23,
158-167).
Some steps in the process require that the dependent matrix be constrained
by
2011 Jul 07
0
Problem with varpart (vegan library)
Hi,
I did a linear regression with 5 explanatory variables. Now, to see the
contribution of each variable, I use varpart from vegan library. But
varpart don?t accepts my 5 explanatory variables, it accept only 4.
1- How must I do to use my 5 explanatory variables?
2- Is it the sum of variance fraction of each variable must be equal to 1.
Thanks for your help.
Komine
--
View this
2011 Nov 17
0
aov how to get the SST?
Hello,
I currently run aov in the following way:
> throughput.aov <- aov(log(Throughput)~No_databases+Partitioning+No_middlewares+Queue_size,data=throughput)
> summary(throughput.aov)
Df Sum Sq Mean Sq F value Pr(>F)
No_databases 1 184.68 184.675 136.6945 < 2.2e-16 ***
Partitioning 1 70.16 70.161 51.9321 2.516e-12 ***
No_middlewares 2 44.22
2002 Dec 13
1
Surprising results from summary(lm()) on data with NO variation
I have some data (from Affymetrix experiments) where I fit an aov() model to
a large number of outcome variables. A reasonable fraction of the outcome
variables have 0 variability because values below a cutoff have been
replaced with the cutoff value (often 20) .
In this case, the overall p-value from summary(lm(..)) is misleadingly
small:
For example (equivalent results in R 1.6.1 on both
2009 Jun 22
2
Help needed: Fraction for Histogram > 1 ???
I have been trying to draw histogram for my manscript and found some strange
things that I could not figure out why.
Using the same code listed below I have successfully draw histograms for a
few figures with fraction labeled on Y axis less than 1 (acturally between 0
to 0.1). But one dataset gives the Y axis label 0 to 5 as fraction. This
is not true, as fraction are less than 1, although the
2010 May 01
1
bag.fraction in gbm package
Hi, Dear Greg,
Sorry to bother you again.
I have several questions about the 'gbm' package.
if the train.fraction is less than 1 (ie. 0.5) , then the* first* 50% will
be used to fit the model, the other 50% can be used to estimate the
performance.
if bag.fraction is 0.5, then gbm use the* random* 50% of the data to fit the
model, and the other 50% data is used to estimate the
2011 Feb 08
1
which multivariate regression?
Hi R-Users,
I have a student doing work with lionfish and she has been trying to analyse
a multivariate dataset to see what variables/factors are influencing the
behaviour of lionfish. We have attempted a number of analyses, including
rpart, relimpo and standard linear regression but we are not having much
luck with quality output. The data is very non-normal and we would
appreciate some advice
2012 Oct 01
2
mlogit and model-based recursive partitioning
Hello:
Has anyone tried to model-based recursive partition (using mob from package
party; thanks Achim and colleagues) a data set based on a multinomial logit
model (using mlogit from package mlogit; thanks Yves)?
I attempted to do so, but there are at least two reasons why I could not.
First, in mob I am not quite sure that a model of class StatModel exists for
mlogit models. Second, as
2008 Feb 01
1
calculation fraction/ratio
Dear R users
I wonder if there is a quick way to calculate the ratio/fraction of a
list/data frame. For example, if I have a data frame with two fields:
"Index" and "A". I would like to know the fractions of A's within the same
"Index". That is, for Index =1, three fractions will be "1/(1+2+3)=0.17",
"2/(1+2+3)=0.33", and
2005 Sep 18
1
trimmed mean in R seems to round the trimming fraction
subject: trimmed mean in R seems to round the trimming fraction
to r-help at stat.math.ethz.ch.
Consider the following example of 10 numbers. 10% trimmed mean is correct
but you can see that the result is the same for many trimming fractions
till 0.20!
For example 13% trimmed mean should use interpolation of second and
eighth ordered observation. R does not seem to do this.
The correct 13%
2009 Feb 25
0
R, joint scaling test, quantitative genetic analysis & sensitivity to model violations
Hi all, This is really a stats question as much as an R question. I'm
trying to do a joint scaling test (JST - see below) on some very
oddly-distributed data and was wondering if anyone can suggest a good way of
dealing with model violations and/or using R to evaluate how sensitive the
model is to violations of the normality assumption.
Here's a quick explanation of the analysis, the
2011 Mar 24
1
fraction with timelag
Dear r-help,
I'm having this DF
df <- data.frame(id = 1:6,
xout = c(1234, 2134, 234, 456, 324, 345),
xin= c(NA, 34,67,87,34, NA))
and would like to calculate the fraction (xin_t / xout_t-1)
The result should be:
# NA, 2.76, 3.14, 37.18, 7.46, NA
I am sure there is a solution using zoo... but I don't know how...
Thanks for any help!
Patrick
2012 Mar 11
2
Matrix negative fraction power
Dear list,
I understand that to raise matrix A to power (-1/2) we should use something
like this:
eigen(A)$vectors%*%diag(1/sqrt(eigen(A)$values))%*%t(eigen(A)$vectors)
[from previous discussions:
http://r.789695.n4.nabble.com/matrix-power-td900335.html]
But this will only do it for negative sqrt of the matrix not for other
fraction powers like (-3/2).
Seeing that these things be can done
2006 Feb 14
0
Preserving seconds fraction in PG timestamps when updating?
I have this code:
Link.find(params[:id]).toggle!(''active'')
Before it, its timestamp is:
2005-11-20 20:45:48.741973-07
After:
2005-11-20 20:45:48-07
Why does Rails take it upon itself to truncate the
seconds fraction? How can I get Rails to not change
it?
Thanks,
csn
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2005 Sep 23
1
dial (iax/X&sip/y) get y fraction earlier
Hello
I like to call to 2 providers
provider X = IAX
provider Y = SIP
exten => _06.,1,Dial(IAX2/X/${EXTEN},30,r)&(SIP/${EXTEN}@Y.Y.Y.Y)
exten => _06.,2,Hangup
Provider X is working but provider Y never shows up.
What's wrong ??
How can I get provider Y working a fraction earlier the provider X
Thanks
Sjaak
2017 Oct 05
0
fraction of null deviance explained by each node/variable in regression trees
I have used packages rpart, mvpart and tree for classification and
regression trees. I want to calculate fraction of null deviance explained
by each node and variable in the tree. For instance, at the first split,
this would be (1 - (sum of residual deviance in each of the two
leaves)/deviance at the root). In the subsequent splits, this formula is
slightly different.
There probably is a function
2007 Jul 10
1
Fraction ECDF
Hi all,
I would like to plot part of the emperical CDF. Suppose the variable is x, I
just need the part when x>1,therefore, I am using the following codes.
tail <- x>1
plot(ecdf(x[tail]), do.points=FALSE, verticals=TRUE)
The "x" value starts from 1, but the yaxs still begins from 0, not the
corresponding value when "x" is 1. How can I make it match?
Could anyone
2010 May 16
0
two level fraction factorial design: How to input 'defining relation'?
I am trying to find the important factors from a two level fraction
factorial design (2^{8-4})
I have studied the companion of vikneswaran but would really like a
basic example of how to do this: (adapted to 8 factors):
mydata<-read.table("myfile.txt", header=T)
summary(aov(resp ~ A*B*C*D*E*F*G*H, data = mydata))
However i can't figure out how the input files are supposed to
2011 May 05
7
Draw a nomogram after glm
Hi all R users
I did a logistic regression with my binary variable Y (0/1) and 2
explanatory variables.
Now I try to draw my nomogram with predictive value. I visited the help of R
but I have problem to understand well the example. When I use glm fonction,
I have a problem, thus I use lrm. My code is:
modele<-lrm(Y~L+P,data=donnee)
fun<- function(x) plogis(x-modele$coef[1]+modele$coef[2])